My current skin-care and hair-care pursuit: Finding an oil that balances the skin and scalp without leaving a trace of being there. It’s a tall order and only the best-of-the-best find their way to empties status. I’ve long loved argan oil for its ability to, at once, mend damage and help protect hair from hot tools, but lately, it’s the castor oil benefits for hair that have been catching my attention.

“Castor oil comes from the seeds of a castor bean plant known as Ricinus communis,” says Dominic Burg, MD, chief scientist and hair biologist at Evolis Professional. “It’s considered to be poisonous, but the oil extracted from the seeds is quite beneficial for the hair.”

Like plenty of other natural oils (such as tea tree and eucalyptus, for instance), castor oil is pretty good at resetting strands, especially after excessive damage. “Castor oil is commonly used to ward off skin infections since it’s a known antibacterial, anti-fungal ingredient,” says Dr. Burg. Another perk? It’s rich in fatty acids. “The oil’s high in vitamin E and omega 6 fatty acids, so it works as a brilliant hair conditioner and natural emollient.”

It’s also good for helping to revitalize your strands, according to Pedro Catalá, pharmacist, cosmetologist, and founder of Twelve Beauty. “It leaves the hair brighter also due to its high concentration of antioxidants.” He adds that it’s also rich with proteins and other nourishing minerals, which help to strengthen hair and over time with repeated use make it stronger—which is good news if you’re a hot-tool user.

People also buzz about castor oil being a superstar to promote hair growth—which is somewhat true. “Castor oil has been shown in a study to increase hair luster, and though a lot of people say the ingredient is helpful for hair growth, there are no studies showing that it directly causes this,” says Hadley King, MD, a board-certified dermatologist, who notes that there are plenty of anecdotal stories. “The thinking is that the ricinoleic acid in castor oil activates a prostanoid receptor and has been shown to increase synthesis of some tissues in vitro, and we know that what it activates can be helpful for hair growth,” she says, pointing to Latisse as a case in which the same effect occurs. “So this could be a possible mechanism of action.”

The thing about castor oil is that it’s very dense, so it’s important to use it on your hair correctly and sparingly. “It doesn’t spread very well, so it takes forever to wash off, which can have a negative impact on the hair and scalp health,” says Catalá. Dr. Burg notes it “can be quite sticky and shouldn’t be used on its own.”

Either use the oil sparingly or concoct your own castor oil hair serum. “I suggest blending with a carrier oil like jojoba or coconut, and mix a minimum of four parts carrier oil and one part castor oil,” recommends Dr. Burg. I don’t know about you, but I’m two seconds away from pouring it all over my head. Keep scrolling to learn more about the many castor oil benefits for hair that your strands need to know about.

Castor oil benefits for hair

1. It’s uber-hydrating and reparative: Since castor oil is a thick extract, it’s good for nourishing your hair. “Castor oil will protect your damaged ends from becoming overly parched due to the detergents found in shampoos or even the harshness of water,” says Dr. Burg. “Apply on the mid-lengths to help alleviate the dryness.”

2. It protects your hair from heat: If you apply castor oil to your strands, it’ll essentially act as a heat protectant, which is particularly good if you’re doing heat styling. “Apply the oil on semi-dry ends,” recommends Dr. Burg. “It protects against high heat appliances and helps to prevent frizzy results.”

3. It helps split ends: One perk I’m especially excited about is that it’s a good treatment for those dreaded split ends. “It’s a great split end mender,” says Dr. Burg. “Apply it on your dry hair as the last step in your styling process. It keeps frizzies at bay, in addition to smoothing the cuticle down to prevent the split ends.”

4. It can help with hair loss: As mentioned above, it’s been a major beauty myth that castor oil can help your hair grow. While there aren’t any studies about that, Catalá notes that it can help when it comes to hair loss. “Castor oil can be used on the scalp to help prevent and repair hair loss,” he says, adding that research even backs up that it could help.

5. It can help treat folliculitis: Folliculitis and dandruff are a pain, but they’re thankfully easy to treat, and castor oil can help with that situation. “Castor oil’s potentially beneficial for the treatment of folliculitis, dandruff, and scalp infections,” says Catalá. That’s due to the oil’s antifungal and antimicrobial properties.

6. It balances the pH of your scalp: Just like with your skin and nails, it’s good to balance the pH of your scalp, too. “The ricinoleic acid content in castor oil helps to balance the pH to your scalp, restoring the damage caused by harsh shampoos,” says Catalá. Fabulous.

How to use castor oil in your hair

To reap the benefits of the hair-nourishing ingredient for yourself, it’s best to dilute it first. This is what Dr. Burg recommends:

1. Mix four parts of a carrier oil (jojoba or coconut oil both work) with one part castor oil.

2. Blend together, then apply to ends as the last step in your styling process, or before you shampoo.

Castor oil for eyelashes and eyebrows

Although there isn’t research to support the purported benefits of castor oil for eyelash and eyebrow growth, people claim that it works. If you end up using castor oil for longer eyelashes and fuller eyebrows, you should use pure castor oil, and we recommend doing a patch test on your skin to see if you have any adverse reactions. Here’s how to use castor oil on your eyelashes and eyebrows:

1. Remove any makeup or dirt from your eyelashes and eyebrows with a gentle cleanser.

2. Dip a cotton swab into the castor oil and apply it to your lash line and eyebrows. Avoid getting the oil in your eyes as this may cause irritation.

3. Leave on overnight and rinse off any excess oil in the morning with warm water or a gentle makeup remover.

The best type of castor oil

There are two types of castor oil people use for beauty purposes, cold-pressed castor oil and Jamaican black castor oil. Regardless of which you choose, make sure that you select a brand that is made with pure castor oil.

Heritage Store Organic Cold Pressed Castor Oil — $18.00

Use this organic, cold-pressed castor oil in your hair or on your eyelashes and eyebrows.

Tropic Isle Living Jamaican Black Castor Oil — $13.00

If you prefer to use Jamaican black castor oil, we recommend Tropic Isle Living.

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